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Global warming increases risk of civil war in Africa, Stanford researchers say

Climate change is likely to increase the number of civil wars raging in Africa, according to Stanford researchers. Historical records show that in warmer-than-average years, the number of conflicts rises. The researchers predict that by 2030, Africa could see a greater than 50 percent increase in civil wars, which could mean an additional 390,000 deaths just from fighting alone.

Climate change could increase the likelihood of civil war in sub-Saharan Africa by over 50 percent within the next two decades, according to a new study led by a team of researchers at Stanford University, the University of California-Berkeley, New York University and Harvard University. The study is to be published online this week by the Proceedings of the National Academy of Sciences (PNAS).

The study provides the first quantitative evidence linking climate change and the risk of civil conflict. It concludes by urging accelerated support by African governments and foreign aid donors for new and/or expanded policies to assist with African adaptation to climate change.

"Despite recent high-level statements suggesting that climate change could worsen the risk of civil conflict, until now we had little quantitative evidence linking the two," said Marshall Burke, the study's lead author and a researcher at Stanford’s Program on Food Security and the Environment when the study was done. "Unfortunately, our study finds that climate change could increase the risk of African civil war by over 50 percent in 2030 relative to 1990, with huge potential costs to human livelihoods."

In the study, the researchers first combined historical data on civil wars in sub-Saharan Africa with rainfall and temperature records across the continent. They found that between 1980 and 2002, civil wars were significantly more likely in warmer-than-average years, with a 1-degree Celsius increase in temperature in a given year raising the incidence of conflict across the continent by nearly 50 percent.

Projected change in African civil war by 2030 as a result of climate change

Building on this historical relationship between temperature and conflict, the researchers then used projections of future temperature and precipitation change to quantify future changes in the likelihood of African civil war. Based on climate projections from 20 global climate models, the researchers found that the incidence of African civil war could increase roughly 55 percent by 2030, resulting in an additional 390,000 battle deaths if future wars are as deadly as recent wars.

All climate models project rising temperatures in coming decades, said David Lobell, study co-author and an assistant professor of environmental Earth system science at Stanford.

"On average, the models suggest that temperatures over the African continent will increase by a little over 1 degree Celsius by 2030," he added. "Given the strong historical relationship between temperature rise and conflict, this expected future rise in temperature is enough to cause big increases in the likelihood of conflict."

To confirm that this projection was not the result of large effects in just a few countries or due to overreliance on a particular climate model, the researchers recalculated future conflict projections using alternate data. "No matter what we tried – different historical climate data, different climate model projections, different subsets of the conflict data – we still found the same basic result," said Lobell, who is also a fellow at the Program on Food Security and the Environment.

"We were definitely surprised that the linkages between temperature and recent conflict were so strong," said Edward Miguel, professor of economics at UC-Berkeley and faculty director of UC-Berkeley's Center for Evaluation for Global Action. "But the result makes sense. The large majority of the poor in most African countries depend on agriculture for their livelihoods, and their crops are quite sensitive to small changes in temperature. So when temperatures rise, the livelihoods of many in Africa suffer greatly, and the disadvantaged become more likely to take up arms."

Marshall Burke Farmers and pastoralists in a maize growing regions of Eastern Kenya.  A new study finds that climate change could severely harm crop productivity and increase the likelihood that disadvantaged rural populations will take up arms.

Farmers and pastoralists in a maize growing regions of Eastern Kenya. A new study finds that climate change could severely harm crop productivity and increase the likelihood that disadvantaged rural populations will take up arms.

Understanding the causes and consequences of civil strife in much of the African continent has been a major focus of the social sciences for decades, said Miguel, given the monumental suffering that has resulted.

It's easy to think of climate change as a long way off, the researchers said, but their study shows how sensitive many human systems are to small increases in temperature, and how fast the negative impacts of climate change could be felt.

"Our findings provide strong impetus to ramp up investments in African adaptation to climate change, for instance by developing crop varieties less sensitive to extreme heat and promoting insurance plans to help protect farmers from adverse effects of the hotter climate," Burke said.

Applying findings from this study could prove useful to policy makers at the upcoming Copenhagen negotiations in December in determining both the speed and magnitude of response to climate change, the authors said.

"If the sub-Saharan climate continues to warm and little is done to help its countries better adapt to high temperatures, the human costs are likely to be staggering," said Burke, who is now a graduate student at UC-Berkeley's Department of Agricultural and Resource Economics.

David Lobell is a center fellow at the Woods Institute for the Environment.

Stanford’s Program on Food Security and the Environment is a joint program of the Freeman Spogli Institute for International Studies and the Woods Institute for the Environment.